The largest number of nonoverlapping Triangles which can be produced by straight Line Segments. The first few terms are 1, 2, 5, 7, 11, 15, 21, ... (Sloane's A006066).
Sloane, N. J. A. Sequence
in ``An On-Line Version of the Encyclopedia of Integer Sequences.''
http://www.research.att.com/~njas/sequences/eisonline.html and Sloane, N. J. A. and Plouffe, S.
The Encyclopedia of Integer Sequences. San Diego: Academic Press, 1995.